How to format $output the right way? - php

Question

I do not know php, I am googling for codes, and I came up on something which I need to do in Wordpress site.
This code shows nothing, but neither brokes site, I think its not correct so can someone help me.
here is the code:
$output.= '<div class="column1">'
$categories = get_the_category();
$separator = ' ';
$output = '';
if($categories) {
$output .= '<div class="above-entry-meta"><span class="cat-links">';
foreach($categories as $category) {
$output .= ''.$category->cat_name.''.$separator;
}
}
$output .='</span></div>';
$output.= '</div> <!-- end column1 -->';
I want to output current post categories via shortcode, and this is one part of the same.
I need just help on how it goes from this example, I ll be able to continue codding by following example.

Answer 1

try this code
$output = '';
$output .= '<div class="column1">';
$args = array( 'orderby' => 'count', 'order' => 'DESC', 'number' => 5 );
$categories = get_the_category($args);
$separator = ' ';
if($categories) {
$output .= '<div class="above-entry-meta"><span class="cat-links">';
foreach($categories as $category) {
$output .= ''.$category->cat_name.''.$separator;
}
}
$output .='</span></div>';
$output.= '</div> <!-- end column1 -->';